Thermal domain Kelvin or Celsius temperature

Question

Hi, I got a question about the temperature unit.

Thermal domain in PLECS which unit I have to use.

According to the help manual, for example, "The temperature difference generated by the component, in kelvin (K). The default is 0."  So, I have to put the temperature in kelvin (K).

but as can be seen in Demo models, it seems to be Celsius (C) i.e. for ambient temperature, the values were 25, meaning room temperature I suppose.

and also you are measuring the temperature of components so if I see a scope y-axis unit for temper. is (C)

All my doubt is from "0K = -273.15°C"

So please help me to understand.

Thanks

Answer 1

Hello,

This can be confusing as we do often use K and C interchangeably in documentation and models. For many of the blocks you will see that the temperature is specified in Kelvin, which relates to a temperature difference. Celsius, on the other hand, is a unit for _absolute_ temperature. It has a different offset but the same scale as Kelvin, i.e. the difference between 12°C and 13°C is 1K.

Note that the Temperature and Thermometer components are modeled in terms of "temperature difference" to make them equally applicable regardless of whether you are choosing a reference point of 0K or 0°C. So essentially, it’s not an issue that both units are available as long as you use a consistent reference point.

Is that clear?

Kris